- dovecot - dovecot.org

Tons of imap-login processes despite client_limit very high
by D D 18 Jul '23

18 Jul '23

Hi Dovecot community. We're seeing a ton of imap-login processes running even when using high performance mode (https://doc.dovecot.org/admin_manual/login_processes/#high-performance-mode) According to the docs: "process_min_avail should be set to be at least the number of CPU cores in the system, so that all of them will be used. Otherwise new processes are created only once an existing one’s connection count reaches client_limit" We have process_min_avail=4, client_limit=0 and default_client_limit=200000. So we'd expect seeing only 4 imap-login processes serving a ton of connections each. Yet, we see thousands of imap-login processes (more than half of all the imap processes): $ ps aux | grep imap-login | wc -l 1278 $ ps aux | grep imap | wc -l 2154 We use verbose_proctitle=yes and a there seem to be 2 types of these processes, about half for a single IP and about half we suspect for multiple IPs: $ ps aux | grep imap-log _apt 1941081 0.0 0.0 10420 8700 ? S 14:57 0:00 dovecot/imap-login [84.115.232.178 TLS proxy] _apt 1941589 0.0 0.0 10532 8648 ? S 14:57 0:00 dovecot/imap-login [119.202.86.160 TLS proxy] _apt 1941789 0.0 0.0 10188 8620 ? S 14:57 0:00 dovecot/imap-login [0 pre-login + 2 TLS proxies] _apt 1942144 0.0 0.0 10716 8748 ? S 14:57 0:00 dovecot/imap-login [0 pre-login + 3 TLS proxies] _apt 1942428 0.0 0.0 10800 8712 ? S 14:57 0:00 dovecot/imap-login [5.41.100.37 TLS proxy] ... $ ps aux | grep imap-log | grep pre-login | wc -l 624 $ ps aux | grep imap-log | grep -v pre-login | wc -l 654 Is having so many imap-login processes normal with our config? Did we misunderstand the docs or is there something wrong here? default_client_limit = 1048576 default_process_limit = 200000 service imap-login { # client_limit = 0 # default is 0 # process_limit = 0 # default is 0 service_count = 100 process_min_avail = 4 vsz_limit = 2G inet_listener imap { } inet_listener imaps { haproxy = yes port = 994 } }

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cram-md5, sasl and lua (inheriting technical debt)
by tknb8＠tunenet.dk 18 Jul '23

18 Jul '23

Hello, I am exploring the posibility of migrating an exsisting setup to postfix+dovecot. The issue being that many clients are currently configured for cram-md5 authentication. I am fully aware that this is a really, really, really bad idea, but re configuring all clients at once is not feasible with limited end user support resources. I have a setup running with LUA for the passdb, and everything works with PLAIN login. To keep compatibility with the PLAIN login mechanism i have tried to store {PLAIN} passwords in the DB, since proper secure password storage is incompatible with CRAM-MD5. My issue is that the LUA function auth_password_verify(req, pass) not even seems to be called for cram-md5 logins. Reading through the documentation also seems to indicate that the callenge is not passed to the LUA function making it impossible to compute the hash in LUA or the function req.password_verify(req, row.password, pass). Is my assumption correct that cram-md5 can not work with a LUA script ? Kind regards, Peter K.

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Many IDLE imap processes but very few connections moved to imap-hibernate
by pierre.alletru＠gmail.com 17 Jul '23

17 Jul '23

Hi Dovecot community! I have a strange issue with imap-hibernate. Or more likely it behaves as it's supposed to and it's just that I don't really understand it. I have enabled it, and it works, but for some reason hibernation happens only to a tiny amount of connections, whereas I have a lot of IDLE imap processes. And I can't find any relevant errors in the logs. ## config ## mail_debug = yes verbose_proctitle = yes $ doveconf imap_hibernate_timeout imap_hibernate_timeout = 5 secs $ doveconf -a | grep -A 21 'service imap-hibernate' service imap-hibernate { chroot = client_limit = 0 drop_priv_before_exec = no executable = imap-hibernate extra_groups = group = idle_kill = 0 privileged_group = process_limit = 0 process_min_avail = 0 protocol = imap service_count = 0 type = unix_listener imap-hibernate { group = $default_internal_group mode = 0660 user = } user = $default_internal_user vsz_limit = 18446744073709551615 B } ## imap processes ## $ ps aux | grep "dovecot/imap" | wc -l 2214 ps aux | grep "dovecot/imap" | grep IDLE | wc -l 1258 $ ps aux | grep "imap-hibernate" syslog 1571453 0.0 0.0 4748 3156 ? S 15:44 0:00 dovecot/imap-hibernate [18 connections] As you can see here I have 1258 IDLE imap processes (out of 2214 in total), and only 18 connections in imap-hibernate. I'd like to have all IDLE processes to be moved to imap-hibernate in order to save up memory. Any idea why these 1k+ IDLE imap processes are not moved into imap-hibernate? Thank you!

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Problem connecting with desktop client
by Wolfgang Paul Rauchholz 17 Jul '23

17 Jul '23

I run my home server under Rocky Linux 9. The server is modem / router and as such has two firewall interfaces; internal and external. Dovecot version is dovecot-2.3.16-8.el9.x86_64 kernel is: 5.14.0-284.18.1.el9_2.x86_64 My domain is wo-lar.com Postfix and Dovecot are up and running, and I can send and receive emails from CLI. But I cannot connect from desktop clients. I get the following error message: Server message: Can't connect to host "tcp://wo-lar.com:143" I tried to telnet from my desktop and server. Results are the same: - I always get a connection refused: telnet wo-lar.com 143 telnet / telnet <Server LAN IP> 143. On server only: telnet 127.0.0.1 143 - telnet wo-lar 143 (without .com!) establishes a connection [root@home wp.rauchholz]# telnet wo-lar 143 Trying 79.152.236.25... Connected to wo-lar. Escape character is '^]'. OK [CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE LITERAL+ STARTTLS AUTH=PLAIN AUTH=LOGIN] Dovecot ready. I went through all kinds for conf files and search for wo-lar string, but can't find it anywhere Where is the mistake hiding? Thanks for helping. Wolfgang

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Re: Replication going away?
by William Edwards 16 Jul '23

16 Jul '23

> Op 16 jul. 2023 om 17:57 heeft Aki Tuomi <aki.tuomi(a)open-xchange.com> het volgende geschreven: > > Hi! > > Yes, director and replicator are removed, and won't be available for pro users either. > > For NFS setups (or similar shared setups), we have documented a way to use Lua to run a director-like setup, see > > https://doc.dovecot.org/3.0/configuration_manual/howto/director_with_lua/ It would probably be good to share this link in the aforementioned Director removal thread. > > Regards to replication, doveadm sync is not being removed. So you can still run doveadm sync on your system to have a primary / backup setup. > > Aki > >> On 16/07/2023 18:34 EEST William Edwards via dovecot <dovecot(a)dovecot.org> wrote: >> >> >> Top posting because nothing specific to reply to, sorry. Not exactly sure, but there’s another thread about the removal of Director in favour of Dovecot Pro on 3.x. Perhaps this change is related. >> >> William Edwards >> >>>> Op 16 jul. 2023 om 16:33 heeft Daniele <danix(a)kernel-panic.it> het volgende geschreven: >>> >>> Hello, >>> >>> Just like Vladimir, I'm a bit concerned about this change, and I'd really appreciate if someone could let us know if the replication feature (that works so well!) will be replaced or removed; and, in case of removal, what would be recommended replacement? >>> Thanks in advance and best regards, >>> Daniele >>> >>>> On 09-Jul-23 9:36 PM, Vladimir Mishonov via dovecot wrote: >>>> Hello everyone. >>>> >>>> Just saw this commit in the official Github repo: >>>> >>>> https://github.com/dovecot/core/commit/4c04e4c30fd4817a8b0e11d04d9681173f69… >>>> >>>> Looking at the commit details, it appears that it completely removes the replication feature. I'm a bit perplexed by this change and am not sure what might be the justification for it. Personally, I find replication to be very useful, as it allows me to maintain a synchronized mirror of all of my mailboxes on my home server, for use as backup in case the primary server goes down for some reason. >>>> >>>> Perhaps there's some sort of replacement being planned for this feature? Or maybe the relevant code is simply going to be refactored to a plugin or external program, and there's nothing to worry about at all? >>>> >>>> In any case, I'd greatly appreciate if one of the developers could comment on this change. >>>> >>> >>> _______________________________________________ >>> dovecot mailing list -- dovecot(a)dovecot.org >>> To unsubscribe send an email to dovecot-leave(a)dovecot.org >>> >> >> _______________________________________________ >> dovecot mailing list -- dovecot(a)dovecot.org >> To unsubscribe send an email to dovecot-leave(a)dovecot.org >

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user lookup fails username is SHA256 @domain
by Daniel Botting 16 Jul '23

16 Jul '23

Hi all, I'm currently building a replacement personal mailserver on Debian 11 (hopefully upgrade it to 12 and it will continue to work). My existing personal mailserver is serving a handful of mailboxes for three domains, virtual users, on an older version of Debian. When I attempt to deliver mail to the server (using swaks) it is accepted by Exim and passed to lda, as per the logs below the lda is somehow seeing the CRYPT entry as if it was the local part? Output from syslog: Jul 16 09:50:02 imap2 dovecot: lda({SHA256-CRYPT}generated-sha(a)example.domain)<700316><>: Debug: auth-master: userdb lookup({SHA256-CRYPT}generated-sha(a)example.domain): Started userdb lookup Jul 16 09:50:02 imap2 dovecot: lda({SHA256-CRYPT}generated-sha(a)example.domain)<700316><>: Debug: auth-master: conn unix:/run/dovecot/auth-userdb: Connecting Jul 16 09:50:02 imap2 dovecot: lda({SHA256-CRYPT}generated-sha(a)example.domain)<700316><>: Debug: auth-master: conn unix:/run/dovecot/auth-userdb (pid=700293,uid=0): Client connected (fd=9) Jul 16 09:50:02 imap2 dovecot: auth: Debug: master in: USER#0111#011{SHA256-CRYPT}generated-sha(a)example.domain#011service=lda Jul 16 09:50:02 imap2 dovecot: auth: Username character disallowed by auth_username_chars: 0x7b (username: {SHA256-CRYPT}generated-sha(a)example.domain) Jul 16 09:50:02 imap2 dovecot: auth: Debug: userdb out: NOTFOUND#0111 Jul 16 09:50:02 imap2 dovecot: lda({SHA256-CRYPT}generated-sha(a)example.domain)<700316><>: Debug: auth-master: userdb lookup({SHA256-CRYPT}generated-sha(a)example.domain): auth USER input: Jul 16 09:50:02 imap2 dovecot: lda({SHA256-CRYPT}generated-sha(a)example.domain)<700316><>: Debug: auth-master: userdb lookup({SHA256-CRYPT}generated-sha(a)example.domain): Userdb lookup failed Jul 16 09:50:02 imap2 dovecot: lda(700316): Debug: auth-master: conn unix:/run/dovecot/auth-userdb (pid=700293,uid=0): Disconnected: Connection closed (fd=9) From what I've read 0x7b is hex for { so disallowed by auth_username_chars line is because of this problem. Doveconf -n output: # 2.3.20 (80a5ac675d): /etc/dovecot/dovecot.conf # OS: Linux 5.10.0-21-amd64 x86_64 Debian 11.6 # Hostname: mailserver.fqdn auth_debug = yes auth_debug_passwords = yes auth_verbose = yes mail_debug = yes mail_location = maildir:~/Maildir namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = } passdb { args = /etc/vmail/%d/passwd driver = passwd-file } protocols = " imap" service auth { unix_listener auth-client { group = Debian-exim mode = 0660 } } service stats { unix_listener stats-reader { group = vmail mode = 0660 user = vmail } unix_listener stats-writer { group = vmail mode = 0660 user = vmail } } ssl = required ssl_cert = </path/to/cert.pem ssl_client_ca_dir = /etc/ssl/certs ssl_key = # hidden, use -P to show it userdb { args = uid=vmail gid=vmail home=/var/local/vmail/%d/%u driver = static } Example of line in passwd file: username:{SHA256-CRYPT}generated-sha I followed https://doc.dovecot.org/configuration_manual/howto/simple_virtual_install/ before posting to ensure I hadn't missed something obvious. Any thoughts on this would be appreciated. Thanks Daniel

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Windows 11 Outlook 365 and dovecot
by The Doctor 16 Jul '23

16 Jul '23

Are there any known Idssues? I help set up a client this morning using Win11 and Dovecot and the client cannot delete e-mail like he did previously. -- Member - Liberal International This is doctor(a)nk.ca Ici doctor(a)nk.ca Yahweh, King & country!Never Satan President Republic!Beware AntiChrist rising! Look at Psalms 14 and 53 on Atheism https://www.empire.kred/ROOTNK?t=94a1f39b We look outside to find assurance, and then we fail. -unknown Beware https://mindspring.com

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Options to track performance?
by Christian 15 Jul '23

15 Jul '23

Hi there, after upgrading my dovecot on a bookworm container, I now have a weird delay when imap clients like Evolution connect the first time. Is there any performance logging configuration I could enable, to see what dovecot is doing in which timing? I suspect some timeout or delay somewhere, but unable to find it so far. Kind regards Chris

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Options to track performance?
by Christian 15 Jul '23

15 Jul '23

Hi there, after upgrading my dovecot on a bookworm container, I now have a weird delay when imap clients like Evolution connect the first time. Is there any performance logging configuration I could enable, to see what dovecot is doing in which timing? I suspect some timeout or delay somewhere, but unable to find it so far. Kind regards Chris

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dovecot and argonid
by Maciej Milaszewski 13 Jul '23

13 Jul '23

Hi For test I try use new auth (argonid) fot dovecot-2.3.20 I change only in sql: password: {ARGON2ID}........ in dovecot.conf i set default_vsz_limit = 2000 M and I can't auth Jul 12 15:07:43 dovecot8 dovecot: auth-worker(44928): conn unix:auth-worker (pid=23437,uid=114): auth-worker<4772376>: sql(user12,xxx.xxx.xxx.12,<VfN04EkA0LUK>): Password mismatch Jul 12 15:07:43 dovecot8 dovecot: imap-login: Disconnected: Connection closed (auth failed, 1 attempts in 105 secs): user=<user12>, method=PLAIN, rip=xxx.xxx.xxx.12, lip=xxx.xxx.xxx.12, secured, session=<VfN04EkA0LUK> I try telnet ip 144 a login username pass Any idea ?

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